1. Field of the Disclosure
The present disclosure relates to an organic light emitting display device, and more particularly, to control of a peak luminance of an organic light emitting display device such as that used in a display panel.
2. Discussion of the Related Art
With the advancement of multimedia, the importance of flat panel display (FPD) devices is increasing. Therefore, various FPD devices such as liquid crystal display (LCD) devices, plasma display panel (PDP) devices, and organic light emitting display devices are being used in practice. In such FPD devices, the organic light emitting display devices may typically have a fast response time of 1 ms or less, low power consumption, and no limitation in viewing angle because the organic light emitting display devices self-emit light. Accordingly, the organic light emitting display devices are attracting much attention as next generation FPD devices.
General organic light emitting display devices may apply a data voltage to each of a plurality of pixels to control a current flowing in an organic light emitting element according to a data current corresponding to the data voltage, thereby displaying a certain image.
Because the organic light emitting element is a self-emitting element, power consumption is changed according to an image. Therefore, by using a peak luminance control method, when an input image is a dark image, organic light emitting display devices of the related art increase a luminance of an image to realize a moving image, but when an input image is a bright image, the related art organic light emitting display devices decrease a luminance of an image to reduce power consumption.
A related art peak luminance control method detects an average picture level from an image of one frame, generates a peak luminance gain value according to the detected average picture level, and adjusts a luminance of the image on the basis of the generated peak luminance gain value. For example, when an input image is a dark image, the peak luminance gain value is generated as a relatively high value for increasing a luminance of the image, but when an input image is a bright image, the peak luminance gain value is generated as a low value for decreasing a luminance of the image.
However, in the organic light emitting display device using the related art peak luminance control method, and as illustrated in FIG. 1, when an input image is changed from a dark image to a bright image, a high peak luminance gain value calculated from the dark image is applied to the bright image to momentarily increase a current flowing in a display panel, and thus, a power supply or the like may be shut down due to the momentary peak current. While the adverse effects caused by this momentary peak current can be remedied when data to be displayed in a display panel is delayed for a time corresponding to one frame by using a frame memory, the cost of the display panel increases due to this frame memory.